The research is designed to elucidate the manner in which the decision to move the eyes is translated into the pattern of excitatory and inhibitory neural impulses channeled to the muscle fibers of the twelve extraocular muscles in the primate. Experiments are to be carried out on monkeys. Visual and vestibular stimulation is given to an alert monkey in whom electrodes have been implanted and the eye movement responses are correlated to unit firing. Such experiments, and the knowledge obtained from post-mortem histology, will enable the tracing of the supranuclear pathways which are utilized by the saccadic, pursuit, vergence and vestibular eye movement systems. BIBLIOGRAPHIC REFERENCE: G. Westheimer and S.M. Blair: "The Ocular Tilt Reaction - A Brainstem Motor Routine" Investg. Ophthalmology 14: 833-840, 1975.